A light emitting diode (LED) is a semiconductor light emitting device that converts electric current into light.
The wavelength of light emitted from the light emitting diode is determined depending on a semiconductor material used to manufacture the light emitting diode. This is because the wavelength of the emitted light corresponds to a band gap of the semiconductor material, which is defined as an energy difference between electrons in the valence band and electrons in the conduction band.
Recently, in line with an increase in brightness of the LED, the LED is used as light sources for display apparatuses, vehicles and illumination apparatuses. Upon a combination of LEDs having a variety of colors or a use of phosphors, an LED emitting white light can be realized with excellent luminous efficiency.